Work around preloaded enums being broken on early PHP 8.4 versions wi…

…th observers (#3093) See also php/php-src#17715. Relatively simple fix: just initialize the cache slots on every request. Has a slight per request-overhead, but avoids crashes when SomePreloadedEnum::cases(). Signed-off-by: Bob Weinand <[email protected]>
DataDog · Feb 20, 2025 · 3a910f7 · 3a910f7
1 parent c5148ba
commit 3a910f7
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Showing 5 changed files with 61 additions and 3 deletions.
diff --git a/Makefile b/Makefile
@@ -112,7 +112,7 @@ $(BUILD_DIR)/run-tests.php: $(if $(ASSUME_COMPILED),, $(BUILD_DIR)/configure)
 	sed -i 's/\bdl(/(bool)(/' $(BUILD_DIR)/run-tests.php # this dl() stuff in run-tests.php is for --EXTENSIONS-- sections, which we don't use; just strip it away (see https://github.com/php/php-src/issues/15367)
 
 $(BUILD_DIR)/Makefile: $(BUILD_DIR)/configure
-	$(Q) (cd $(BUILD_DIR); ./configure --$(if $(RUST_DEBUG_BUILD),enable,disable)-ddtrace-rust-debug $(if $(ASAN), --enable-ddtrace-sanitize) $(EXTRA_CONFIGURE_OPTIONS))
+	$(Q) (cd $(BUILD_DIR); $(if $(ASAN),CFLAGS="${CFLAGS} -DZEND_TRACK_ARENA_ALLOC") ./configure --$(if $(RUST_DEBUG_BUILD),enable,disable)-ddtrace-rust-debug $(if $(ASAN), --enable-ddtrace-sanitize) $(EXTRA_CONFIGURE_OPTIONS))
 
 $(SO_FILE): $(if $(ASSUME_COMPILED),, $(ALL_OBJECT_FILES) $(BUILD_DIR)/compile_rust.sh)
 	$(if $(ASSUME_COMPILED),,$(Q) $(MAKE) -C $(BUILD_DIR) -j)

diff --git a/ext/ddtrace.c b/ext/ddtrace.c
@@ -1622,7 +1622,7 @@ static void dd_initialize_request(void) {
 static PHP_RINIT_FUNCTION(ddtrace) {
     UNUSED(module_number, type);
 
-#if PHP_VERSION_ID < 80000
+#if PHP_VERSION_ID < 80000 || (PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500)
     zai_interceptor_rinit();
 #endif
 

diff --git a/ext/live_debugger.c b/ext/live_debugger.c
@@ -27,7 +27,14 @@ static void clean_ctx(struct eval_ctx *ctx) {
         zend_arena *arena = ctx->arena;
         do {
             zend_arena *prev = arena->prev;
-            for (zval *cur = (zval *)((char *)arena + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))); cur < (zval *)arena->ptr; ++cur) {
+#ifdef ZEND_TRACK_ARENA_ALLOC
+            for (zval **ptr = (zval **)arena->ptrs; ptr < (zval **)arena->ptr; ++ptr)
+            {
+                zval *cur = *ptr;
+#else
+            for (zval *cur = (zval *)((char *)arena + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))); cur < (zval *)arena->ptr; ++cur)
+            {
+#endif
                 zval_ptr_dtor(cur);
             }
             arena = prev;

diff --git a/zend_abstract_interface/interceptor/php8/interceptor.c b/zend_abstract_interface/interceptor/php8/interceptor.c
@@ -913,12 +913,20 @@ void zai_interceptor_execute_internal_with_handler(INTERNAL_FUNCTION_PARAMETERS,
 }
 #endif
 
+#if PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500
+zend_internal_function **preloaded_enum_functions = NULL;
+#endif
+
 void zai_interceptor_setup_resolving_post_startup(void);
 
 // extension handles are supposed to be frozen at post_startup time and observer extension handle allocation
 // incidentally is right before the defacto freeze via zend_finalize_system_id
 static zend_result (*prev_post_startup)(void);
 zend_result zai_interceptor_post_startup(void) {
+#if PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500
+    uint32_t classes = zend_hash_num_elements(CG(class_table));
+#endif
+
     zend_result result = prev_post_startup ? prev_post_startup() : SUCCESS; // first run opcache post_startup, then ours
 
     zai_hook_post_startup();
@@ -931,6 +939,34 @@ zend_result zai_interceptor_post_startup(void) {
     zai_interceptor_avoid_compile_opt = true; // Reset it in case MINIT gets re-executed
 #endif
 
+#if PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500
+    if (classes != zend_hash_num_elements(CG(class_table))) {
+        // We suppose some preloading happened here
+        zend_class_entry *ce;
+        int num = 0;
+        ZEND_HASH_FOREACH_PTR(CG(class_table), ce) {
+            if ((ce->ce_flags & ZEND_ACC_ENUM) && ce->type != ZEND_INTERNAL_CLASS) {
+                num += ce->enum_backing_type == IS_UNDEF ? 1 : 3;
+            }
+        } ZEND_HASH_FOREACH_END();
+        if (num) {
+            preloaded_enum_functions = pemalloc(sizeof(zend_function *) * (num + 1), 1);
+            int idx = 0;
+            ZEND_HASH_FOREACH_PTR(CG(class_table), ce) {
+                if ((ce->ce_flags & ZEND_ACC_ENUM) && ce->type != ZEND_INTERNAL_CLASS) {
+                    zend_function *function;
+                    ZEND_HASH_FOREACH_PTR(&ce->function_table, function) {
+                        if (!ZEND_USER_CODE(function->type)) {
+                            preloaded_enum_functions[idx++] = &function->internal_function;
+                        }
+                    } ZEND_HASH_FOREACH_END();
+                }
+            } ZEND_HASH_FOREACH_END();
+            preloaded_enum_functions[idx] = NULL;
+        }
+    }
+#endif
+
     return result;
 }
 
@@ -1008,6 +1044,18 @@ void zai_interceptor_activate(void) {
 #endif
 }
 
+#if PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500
+void zai_interceptor_rinit(void) {
+    if (preloaded_enum_functions) {
+        zend_internal_function **zif = preloaded_enum_functions;
+        size_t cache_size = zend_internal_run_time_cache_reserved_size();
+        do {
+            ZEND_MAP_PTR_SET((*zif)->run_time_cache, zend_arena_calloc(&CG(arena), 1, cache_size));
+        } while (*++zif);
+    }
+}
+#endif
+
 void zai_interceptor_deactivate(void) {
     zend_hash_destroy(&zai_hook_memory);
     zend_hash_destroy(&zai_interceptor_implicit_generators);

diff --git a/zend_abstract_interface/interceptor/php8/interceptor.h b/zend_abstract_interface/interceptor/php8/interceptor.h
@@ -12,5 +12,8 @@ void zai_interceptor_startup(void);
 void zai_interceptor_activate(void);
 void zai_interceptor_deactivate(void);
 void zai_interceptor_shutdown(void);
+#if PHP_VERSION_ID >= 80400 && PHP_VERSION_ID < 80500
+void zai_interceptor_rinit(void);
+#endif
 
 #endif  // ZAI_INTERCEPTOR_H